The present invention relates to a device for automatically anchoring the outer thread end of a ball wound on an automatic balling machine. The invention relates further to a process for operating the balling machine pursuant to the invention, whereby the lapping thread is guided in front of the front end of the winding mandrel after termination of the lapping process.
Devices and processes for the automatic anchoring of the outer thread end of balls are known to the art from the German patent specification No. 2,513,144 and from the French patent specification No. 1,057,920. The German patent specification No. 2,513,144 discloses an umbrella mandrel for known automatic balling machines, which machines can be equipped with a number of winding mandrels arranged horizontally or diagonally as spindles. A rotating winding arm, a cutting device, a thread guide, and gripping devices for pulling the ball off the winding mandrels are assigned to each winding mandrel. In this device, the thread is guided after the termination of the lapping process by the winding arm and the thread guide in front of the front end of the winding mandrel, cut by the cutting device, and the thread end sucked into a suction tube arranged inside of the mandrel and thereby held fast or anchored. The suction tube extends over the entire length of the winding mandrel and is at the same time designed as a push rod for the actuation of the umbrella stretchers of the umbrella mandrel. Located at the rear end of the suction tube is a connection to a vacuum pump which provides the suction necessary for anchoring the thread end. A high suction output of the vacuum pump is required for this method of securing the thread end. The energy required for the generation of the suction stream in the suction tube can thereby be substantially greater than the energy required for driving the winding mandrel. Depending on the thickness and type of thread, the end of the thread can be sucked more or less effectively into the suction tube, resulting in considerable differences in the work flow and operation of the winding device. This necessitates frequent adjusting of the winding device to the various yarn and/or thread types, or else malfunctions in the machinery will occur which lead to undesirable disruption in the operation.
The French patent specification No. 1,057,920 shows also an umbrella mandrel with a winding arm and cutting device. The cut end of the thread is secured in this device by inserting the lapping thread through the winding arm into a hook provided at the front end of the winding mandrel. This hook is pulled with the inserted end of the thread by a drawbar into the inner cavity of the core of the winding mandrel which is fashioned as a tube. The thread is thereby anchored and pulled into the interior of the ball when the latter is pulled off the umbrella mandrel. The disadvantage in this device is that the lapping thread can become caught in the hook, with the result that the ball cannot be completely pulled off. In addition, fibers of the lapping thread remain hanging on the hook, with the result that the insertion of the lapping thread into the hook is prevented after a certain period of operation and the anchoring of the thread end becomes impossible. Prior to cutting the thread, the winding arm, winding mandrel and cutting device must be brought into an exactly predetermined position, so that the lapping thread can be inserted into the hook and also remains there.
The present invention has the task of avoiding the disadvantages present in the known state of the art and of presenting a solution which does not require additional driving power for anchoring of the thread, and whereby the thread can be anchored in any desired position after having been guided over the front end of the winding mandrel. The invention also should make it possible to treat every thickness and type of thread the same.